I don't blame you. I guess my circle of friends is widely dispersed enough that I'm used to having to clarify "there was this post over somewhere else, and I want to talk about it here (too)"?

Would leaving it a "I was talking about X somewhere else, here are my thoughts", no mention of the other person at all, work for you? Or even shearing the suggestion of conversation out of it at all: "I was reading about X somewhere else, here are my thoughts"?